Nitric Acid → 2-Methyl-7-nitro-1,2,3,4-tetrahydroquinoline

HRID 494189

Reaction equation

[CH3:1][CH:2]1[CH2:11][CH2:10][C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[NH:3]1.[N+:12]([O-])([OH:14])=[O:13].[OH-].[Na+]>S(=O)(=O)(O)O>[CH3:1][CH:2]1[CH2:11][CH2:10][C:9]2[C:4](=[CH:5][C:6]([N+:12]([O-:14])=[O:13])=[CH:7][CH:8]=2)[NH:3]1

Participants

Conditions

Temperature: 2.5 °C

Procedure

To a solution of 2-methyl-1,2,3,4-tetrahydroquinoline (D63) (383 mg, 2.6 mmol) in concentrated sulfuric acid (7.2 ml) at 0-5° C. was added concentrated nitric acid (0.26 ml) dropwise so as to maintain the temperature at 0-5° C. On completion of addition, the mixture was warmed to room temperature, stirred for 45 mins. then poured onto crushed ice and neutralised with 2M sodium hydroxide solution. The mixture was extracted with DCM which was washed with brine, dried over MgSO4 and concentrated in vacuo to give the crude product which was purified by flash column chromatography. Elution with 10% EtOAc in 60-80° C. petroleum ether gave the title compound as an orange solid (297 mg). 1H NMR (400 MHz, CDCl3) δ (ppm): 7.40 (dd, 1H), 7.27 (d, 1H), 7.03 (d, 1H), 4.01 (br, 1H), 3.46 (m, 1H), 2.87 (m, 2H), 1.92 (m, 1H), 1.59 (m, 1H), 1.24 (d, 3H).

Workup

additionOn completion of addition
temperaturethe mixture was warmed to room temperature
additionthen poured
customonto crushed ice
extractionThe mixture was extracted with DCM which
washwas washed with brine
dry with materialdried over MgSO4
concentrationconcentrated in vacuo
customto give the crude product which
customwas purified by flash column chromatography
washElution with 10% EtOAc in 60-80° C. petroleum ether

Sources & evidence

ORD record: ord-501884145ff140e59d22e26d12c64f9d
Source dataset: uspto-grants-2009_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07538121B2

Linked notes

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